Screening devices of the kind described in the preceding paragraph are known per se. In order to provide large mesh sizes and to screen out larger particles, the web consists of a flexible filter material, for example, a wire mesh a mesh that is made up of thick plastic fibers. In order to filter out smaller particles, so-called filter cloths are used; these generally consist of a textile material. For purposes of simplicity, reference hereinafter will be made to such filter cloth or cloths, without the invention being restricted to the use of such filter cloths.
In many screening or filtering systems, there is frequently a need to change the screening cartridge or a plurality of screening cartridges, or else simply replace the filter cloth, which may have become damaged or clogged.
In conventional screening devices, it is relatively costly to change the filter cloth, for it has to be clamped tightly within the frame in order that no unfiltered material passes the filter cloth.